Modern increases in the burden of chronic disease at older ages are partly a consequence of increased survival and life expectancy made possible by improvements in lifestyle, environmental conditions and medical treatments that influence longevity. We propose an interdisciplinary training program in public health and aging that will prepare our trainees as researchers in public health science and policy to address the causes and consequences of chronic disease in older people and to develop effective programs and policies. Faculty (n=19) from 10+ disciplines in public health and in medicine with outstanding records in doctoral/postdoctoral mentoring and aging research will participate. We will train 16 doctoral and postdoctoral students who will gain the skills and knowledge needed to apply public health science and policy to the problems of aging and chronic disease. This will be accomplished by core coursework, interdisciplinary monthly seminars, practice internships, and co-mentoring by faculty highly experienced in interdisciplinary research and training. Understanding the trajectories of change in health and function among older adults clearly requires longitudinal perspectives that can capture both cumulative and changing exposures. This implies use of methodological and statistical models that permit modeling of time-dependent covariates and simultaneous competing outcomes. Research in older populations has special methodological and conceptual challenges that are not addressed in standard public health programs. Our training program in chronic disease in older adults will address the following issues: 1.) Risk factors, exposures and disease. The effects of risk factors on chronic disease may be time-dependent (early life or mid life vs. late life) due to changes in biology with age, selective survival, or other cofactors that vary over time and with aging. 2.) Primary prevention of chronic disease in older adults. The evidence that disease can be prevented in older populations by altering primary risk factors. 3.) Prevention of disease progression: 4.) Methods of research in aging adults including practical issues of recruitment, retention and more theoretical issues such as methods to measure frailty, cognitive and functional status and disability. 5.) Models in aging including longitudinal analytic techniques, missing data, time-dependent analyses. 6.) Translation into public health practice and policy. This training program is based on the realization that understanding, preventing and managing the consequences of chronic disease in older people is complex and requires a multi-level approach that integrates clinical, biological and psychosocial factors with health care and health policy.